【摘要】 【目的】弄清黎平县耕地土壤重金属生态风险状况,为农作物的安全生产和耕地土壤重金属污染防治提供科学依据,【方法】采用单因子污染指数、内梅罗综合污染指数和Hankanson潜在生态风险指数法,分析黎平县耕地土壤铬(Cr)、铅(Pb)、镉(Cd)、砷(As)和汞(Hg)5种重金属的污染程度,并对其潜在生态风险进行评价。【结果】黎平县耕地土壤Cr、Pb、Cd、As和Hg的平均含量分别为68.39、23.55、0.22、6.16和0.15 mg/kg,Hg平均含量超过贵州省土壤背景值,是其1.36倍。Cr、Pb、Cd、As和Hg的单因子污染指数平均值分别为0.31、0.09、0.74、0.19和0.47,只有Cd超标,超标率为3.4%;内梅罗综合污染指数平均值为0.68,整体无污染;Cd单因子潜在生态风险程度为"低""中"和"较重"的分别占91.5%、6.8%和1.7%,Hg单因子潜在生态风险程度为"低"和"中"的分别占95.9%和4.1%。【结论】黎平县耕地土壤重金属整体上无潜在生态风险,但部分乡镇Cd存在"较重"程度潜在生态风险,Hg存在"中"程度潜在生态风险。更多还原

【Abstract】 【Objective】The aim of this paper was to reveal the ecological risk of heavy metals in farmland soil in Liping County of Qiandongnan prefecture, and provide scientific basis for safe production of crops and prevention and control of heavy metal pollution in farmland soil.【Method】The single factor pollution index, Nemero comprehensive pollution index and Hankanson potential ecological risk index method were used to analyze pollution degree of chromium(Cr), lead(Pb), cadmium(Cd), arsenic(As) and mercury(Hg) in cultivated soil in Liping County, and their potential ecological risks were evaluated as well.【Results】The average concentrations of Cr, Pb, Cd, As and Hg in the soils were 68.39, 23.55, 0.22, 6.16, 0.15 mg/kg, respectively. Hg concentration was 1.36 times as the background value of soil in Guizhou province. The average single factor pollution index of Cr, Pb, Cd, As and Hg were 0.74, 0.47, 0.31, 0.19 and 0.09, respectively. The over standard rates of Cd was 3.4 %. The mean value of Nemerow integrated pollution index was 0.68, indicating that there was no pollution in Liping county. The low, medium and heavier potential ecological risk levels of Cd accounted for 91.5 %, 6.8 % and 1.7 % respectively. The low and medium potential ecological risk levels of Hg accounted for 95.9 % and 4.1 % respectively.【Conclusion】There is no potential ecological risk for heavy metals in cultivated soils in Liping county. However, there is still existence of ecological risk for relative heavy Cd level and moderate Hg level in some villages and towns.更多还原